Electric lamp



Nov. 14, 1933. DOUGLAS 1,935,146

ELECTRIC LAMP Filed Oct. 23, 1929 2 Sheets-Sheet 1 Nov. 14, 1933. H. A.DOUGLAS ELECTRI C LAMP Filed Oct. 23. 1929 2 Sheets-Sheet, 2

Patented Nov. 14, 1933 UNITED STATES PATENT .FFlCE 5 Claims.

My invention relates to lamps which employ lamp receiving sockets-andholders for the sockets. The invention is of particular importance wheresuch a lamp is equipped with a concave reflector which carries theholder whose bore is in register with an opening provided through thereflector. The invention has for its general object the provision ofmeans whereby the lamp may be fixed with respect 'to' said '10. holderand, where the lamp is equipped with a reflector, may be fixed withrespect to the latter element, also. The invention finds particular usein connection with lamps; having parabolic reflectors and enables thefixed relationship of I the lampfilament with-respect to the parabolicaxis on which the filament is preferably located. A lamp thusconstructed will direct light in afixed path with respect to the axis ofthe reflector, thereby avoiding difficulty now fre- I quentlyencounteredin the adaptation of reflecting lamps to automotive vehicles, bodily orother adjustment of the lamps having frequently been required when theusers happen to find that the light is improperlydirected.

In my copending application Serial No. 403,613 filed October 30, 1929,which issued as Patent No. 1,853,514, 1 have broadly claimed a lampreceiving socket within a holder and smaller in cross section than theholder, and means pressing the socket laterally against oneside of theholder. The structure disclosed in the aforesaid copending applicationemploys a concave reflectorwith respect to which the socket holder is-fixed, the bore of the socket holder being in "3'5. register with anopening that is formed through the reflector to permit of the insertionof the base of an incandescent lamp. The structure of the aforesaidapplication is also inclusive oi spaced apart spacing means interveningbetween the holder and socket in the place at which the socket ispressed against the'holder.

The structure of my aforesaidcopending application also includes asingle instrumentality, carried by the holder, which presses directlyupon the base of the'lamp and, through the lamp base, upon the sockettopress the socket against the holder. The structure disclosed in mycopending application Serial No. 401,720 filed October 23, 1929, whichissued as Patent No. 1,873,712 includesone member upon the holder whichpresses upon the. socket to press the socket against the holder andanother member upon the socket which presses the lamp base against thesocket.

.In the structureherein disclosed, the socket is provided with onemember which engages and preferably itself presses upon the lamp baseand the holder is provided with a member which presses upon this memberand, therethrough, upon the lamp base and presses the socket against theholder through the intermediation of the lamp base. The socket is oflesser cross section than the bore of theholder and the lamp base is oflesser cross section than the bore of the socket.

I also desirably provide an improved interengagement between the holderand socket which preferably serves to prevent longitudinal move--' mentof the socket. To this end,'one of these elements is provided with anopening and the other is provided with a lateral projection or pinreceived in this opening. Ifthesocket is to have no movement, theprojection 01' pin is snugly received in said opening. In order toensure accurate engagement of'said projection within said opening theusual entrance slot to the opening is omitted. In order that theprojection may be entered within the opening, a wedging or cam formationis provided upon one of the elements, preferably the element that hasthe opening, and at the end thereof where the assembly of the holder andsocket is initiated. This wedging formation widens the spacingbetweenthe socket andholder, preferably shifting the socket laterally toenable theprojection to pass the" contiguous imperforate portion of theelement having the-opening until the projection is in register with theopening whereupon the member, which is a spring, upon the holder thatpreferably forces the socket laterally against the'holder is effectiveto force the entry of the projection within said opening.

If the holder be associated with-a reflector, the position of the lampfilament with respect to the reflector is assured, it being understoodthat the lamp filaments of the incandescent lamps which are to be usedin the structure of mylinvention preferably occupy predetermined uniformpositions with respect to the lamp bases. I

To'further assure the precise positionsof the from therefiector isfixedly determined. This construction obviates the necessity of aspecial design for the reflector which has hitherto been proposed toprocure the same lighting effect with the filament in diiferentpositions along the reflector axis. The invention, however, is not to bethus limited.

The invention will be more fully explained in connection with theaccompanying drawings, showing the preferred embodiment thereof, and inwhich Fig. l is a plan View with a portion of the reflector shown insection; Fig. 2 is a view from beneath, part of the bulb being brokenaway; Fig. 3 is a side view; Fig. 4 is a sectional View on line 4-4 ofFig. 1; Fig. 5 is a sectional view on line 5-5 of Fig. 4; Fig. 6 is asectional View on line 66 of Fig. 4; Fig. 7 is a perspective Viewillustrating component parts of the structure in separated relation; andFig. 8 is a sectional elevation taken through the axis of the parabolicreflector. V

The lamp illustrated includes a housing or back element 1 having abracket 2 on its bottom side by which it may be assembled with theautomotive vehicle or other support, as indicated. The housing or back 1encloses a parabolic reflector 3 which is formed with a grooved flange 4at its forward end. This flange is pressed against a rim 5, providedupon the housing, by an assembling ring 6. This assembling ring alsopresses the light transmitting closure 7, usually of glass. against'agasket 8 which is seated in the flange 4.

The generally cylindrical socket holder 9 has its forward end passedthrough a circular opening formed through the crown of the reflector, inthe embodiment of the invention shown. The forward end of the holder 9is formed with flanges 10' and 11 between which the surrounding edgeportion of the reflector is clamped, whereby the holder and reflectorare maintained coaxial, in the structure illustrated.

The generallycylindrical terminal carrier or lamp socket 12 is held inassembly with and within the holder 9 by the means hereinafter setforth. This socket is preferably formed with a single bayonet slot orchannel 13 for receiving a bayonet pin or projection 14 upon the base 15of an incandescent lamp. This bayonet pin is maintained in a V-shapedretaining. seat 13' of the bayonet slot by any suitable means, theV-shaped seat holding, the lamp fromrotative movement. The meansillustrated is .inclusive of a coiled spring 16 which surrounds aplunger 17 constituting a circuit terminal and presses forwardly uponthe plunger head 18 and rearwardly upon the flange 19 of a metallicguiding sleeve 20. This guiding sleeve is mounted upon an insulatingdisc 21 which is fixedly assembled with and within the rear end of thesocket 12. The plunger head 18 presses against a contact 22 which iscarried by the generally cylindrical lamp base 15 which is made ofinsulating material. The lamp structure illustrated is asocalled singlepole structure, though the invention is not to be thus limited. Where asingle pole structure is employed, the contact 22 ,is upon the axisofthe lamp base. A stifl leading in wire 24 establishes connection betweenthe contact 22 and one terminal of the filament 25. An-

other stiff leading in, wire 26 establishes a connection between theother terminal of the filament and the metallic sheath 2'? whichsurrounds the insulating portion of the lamp base and, from the point ofview of my invention, also constitute's a part or enlargement of thelamp base. The body of the reflector, the holder 9, and the socket 12are grounded and when the lamp is in place the sheath 27 is alsogrounded as it has connection with the holder, as will more fullyappear.

In carrying out my invention the cross section of the socket 12 issmaller than the bore of the holder 9 and the base of the lamp,inclusive of its sheath 27, is smaller, in cross section, than the boreof the socket.

Spaced apart spacing means intervene between the holder 9 and the socket12. These spacing means are preferably in the form of ribs 28 whichextend longitudinally of the holder and socket. Each rib is desirablyintegrally formed with one of the elements 9 or 12, both ribs beingshown as being integrally formed with the holder. The ribs are spacedless than 180 degrees apart, preferably 120 degrees apart. The means forpressing the socket 12 against the holder 9 is desirably inclusive oftwo spring tongues 29 which are integrally formed with the holder 9. Theholder is formed with a lateral circular opening 30 therethrough and thesocket is provided with a pin or projection 31 which is to enter thisopening. The holder is provided with a cam or wedging portion 32 at therear end thereof where the socket is entered in assembling it with theholder. As the socket is moved forwardly, the pin 31 is directed againstthe cam or wedge 32, whereby the socket is pressed against the springs29 and whereby the projection 31 is entered within the bore of theholder. The pin moves past the imperforate portion of the holder that isbetween the opening 30 and the wedge or cam 32 and when it comesintoregister with the opening 30, the springs 29 press the socket toward theopening to enter said projection within the opening and to engage thesocket with the ribs 28. The portion of the socket which is engaged bythe springs 29 is in the form of a spring tongue 33 which is integrallyformed with the socket. This spring tongue, itself, presses laterallyupon the lamp base and forces the longitudinal ribs 34, that arepreferably provided upon the lamp base, against the socket. The tongue33 also serves to transmit the pressure of the springs 29 bearingthereon to the lamp base, this pressure being further transmittedthrough the lamp base to press the socket against the holder. By thisarrangement the socket is prevented from having longitudinal movement,so that the filament of the lamp is flxed longitudinally of the axis ofthe reflector. By this preferred construction, it is unnecessary tospecially design the reflector as would be desirable if the lamp socketwere movable along the lamp axis. The springs 29 press the socket evenlyagainst the ribs 28, the line of pressure being between these ribs. Inthis way, the axis of the socket is flxed'with respect to thevreflector. The spring 33 exerts pressure on a line between the ribs 34to accurately deflne the position of the lamp lengthwise of thestructure. As the V-shaped bayonet seat 13 prevents rotative movement ofthe lamp the filament of the lamp is accurately positioned with respectto the reflector, this position being predetermined if the filaments ofall lamps to be used in my device are accurately positioned with respectto the lamp bases.

Changes may be made without departing from the invention.

Having thus described my invention, I claim;

1. The combination with a cylindrical holder having a lateral opening,said opening beingentireiy surrounded by the material of the holder; ofa cylindrical terminal carrier received within said holder and having alateral projection snugly 15,0

received in said opening; and a spring tongue integral with the holderupon the side of the holder opposite the opening, said tongue pressingthe carrier laterally of the holder to maintain the projection withinsaid opening.

2. The combination with a cylindrical socket holder having a lateralopening, said opening being entirely surrounded by the material of theholder; of a socket within saidholder and having a lateral projectionsnugly received in said opening; and a spring tongue integral with theholder pressing the socket laterally of the holder to maintain theprojection within said opening, said tongue being opposite the openingin the holder and being curved in the direction of the pe-- riphery ofthe holder.

3. The structure of claim 2 wherein there are two said spring tongueshaving their free ends adjacent a point opposite the opening in theholder and said free ends being turned inwardly of the holder.

4. The combination with a cylindrical socket holder having a lateralcircular opening, ,said opening being entirely surrounded by thematerial of the holder; of a socket within said holder and having acylindrical lateral projection snugly received in said opening, saidholder having a cam formation positioned to be engaged by the projectionwhen the assembly of the holder and a pair of spring tongues integralwith the holder pressing the socket laterally of the holder to enter andmaintain the pro ection within said opening when the projection on thesocket is in register therewith, said tongues being curved in thedirection of the periphery of the holder and having their free endsadjacent a point opposite the opening in the holder, said free endsbeing turned inwardly of the holder.

5. The combination with a cylindrical holder having a lateral opening,said opening being entirely surrounded bythe material of the holder; ofacylindrical terminal carrier received within said holder and having alateral projection snugly receivable in said opening; an outwardlystruck inclined portion on said holder providing a cam upon which theprojection rides to shift the carrier laterally to cause the projectionto ride over the margin of the opening and into said opening;

and a spring tongue integral with the holder upon' the side of theholder opposite the opening, said tongue flexing upon lateral movementof the carrier and thereafter pressing the carrier laterally to maintainthe projection Within the opening.

HARRY A. DOUGLAS.

